A web authoring tool is a tool which allows a user to intuitively create and modify a web page on a GUI screen. With this tool, the web page displayed on an edit screen is substantially the same as the web page outputted as an editing result. Such a feature is called WYSIWYG (What You See Is What You Get), and is a condition for enabling efficient editing. In order to realize this, the web authoring tool requires displaying a web page in a similar manner to that of an actual web browser, based on data indicating layout of the web page.
Data indicating layout of a web page is described using a structured language, such as XML (eXtensible Markup Language). For this reason, displaying the web page requires processing for analyzing contents of such XML data, and the processing takes a certain amount of time. The processing time increases as a structure of the web page becomes more complicated. The processing time directly turns out to be waiting time for a user in a web authoring tool that utilizes a screen display for editing, which may cause decrease in editing efficiency. Although omitting a part of the screen display for reducing the processing time may be considered, important information for editing may not be displayed depending on an omitted part, which may decrease the editing efficiency by contrast.
As a reference technique, Japanese Patent Application Publication No. 2003-345788 proposes a technique for allowing full display and simplified display of an image in an electronic document to be switchable based on external operation by the user or the like. However, this technique only allows switching of the display, and it cannot automatically determine as to which display object should be displayed in a simplified form or hidden for reducing the processing time.